A detection device and method for simultaneous equal-optical-path imaging and equal-illuminance illumination of grain double sides based on combined-image optical elements

Abstract

The present invention discloses a detection device and method for simultaneous equal-optical-path imaging and equal-illuminance illumination of both sides of a grain based on an image combining optical element. The device comprises a camera, a telecentric imaging lens, an image combining optical element and a semiconductor grain arranged in sequence in a vertical light path direction. Trapezoidal image transfer prisms are arranged on both sides between the image combining optical element and the semiconductor grain. The two side surfaces of the semiconductor grain are imaged at different areas on a camera sensor surface through the trapezoidal image transfer prism and the image combining optical element in a dual light path. The present invention replaces two independent right-angle image transfer prisms with a single image combining optical element to realize the image combining function of the double-sided imaging light path. The solution has a simple assembly structure, is easier and more convenient to debug the image combining light path, and has a higher double-sided image combining accuracy.

Description

Technical field:

[0002] The present invention belongs to the field of optical detection and machine vision, and in particular relates to a detection device and method for simultaneous equal optical path imaging and equal illumination illumination of double-sided grains based on a composite image optical element. Background technology:

[0004] The applicant's previous application, titled "Optical detection device and method for realizing equal optical path imaging of two surfaces of semiconductor grains", application number: "2019113692573, wherein the synthesis of the images of the two surfaces of the grain on the CCD sensor requires two right-angle reflection prisms based on total reflection (such as Figure 1 ), or a right-angle double-sided reflecting prism (such as Figure 2 As shown in the figure); the former has high technical difficulty requirements for the precise assembly and debugging of the right-angle reflection prism, and the latter is not a priority option because it needs to be coated with a high-reflection reflective film and reliability. In addition, the 45-degree edges of the right-angle reflection prism are inevitably broken during the processing process. Two adjacent defective edges will affect the recognition and imaging quality of the double-sided image. Therefore, it is necessary to find a solution with controllable double-sided imaging interval and good component manufacturing processability.

[0005] In addition, the applicant has previously applied for two patents, the patent name is: "Method for obtaining completely equal illumination for optical inspection of two opposite sides of semiconductor grains", patent application number: "2019113692588; and the patent name is: "New illumination compensation method for simultaneous detection of defects on both sides of semiconductor grains", patent application number: "201911315115.9. The double-sided imaging optical paths proposed in these two patent applications both require the addition of specific illumination optical elements (optical wedges or right-angle beam splitting prisms) on the right-angle image rotation prism to obtain the purpose of equal illumination for double-sided imaging, such as Figure 3 , 4, 5 as shown, Figure 3 The illumination source system requires an optical wedge, which increases the complexity of the mechanical structure; Figure 4 , 5 illumination source system requires a right angle beam splitter prism resulting in 50% light energy loss. Summary of the invention:

[0007] In view of the above problems, the present invention proposes a detection device and method for simultaneous equal-optical-path imaging and equal-illuminance illumination on both sides of a grain based on an image combining optical element. The optical detection device for equal-optical-path imaging of the two surfaces of a semiconductor grain replaces two independent right-angle image rotation prisms with a single image combining optical element to achieve the image combining function of the double-sided imaging light path. The structure is simple, the debugging is easier and more convenient, and the double-sided imaging accuracy is higher.

[0008] The present invention is a detection device for simultaneous equal-optical-path imaging and equal-illuminance illumination of both sides of a grain based on an image combining optical element, characterized in that it includes a camera, a telecentric imaging lens, an image combining optical element and a semiconductor grain arranged in sequence in a vertical light path direction, trapezoidal image transfer prisms are provided on both sides between the image combining optical element and the semiconductor grain, and the two side surfaces of the semiconductor grain are imaged on different area positions on the camera sensor surface through the trapezoidal image transfer prism and the image combining optical element in a dual light path.

[0009] The present invention is a detection device for simultaneous equal-optical-path imaging and equal-illuminance illumination of both sides of a grain based on an image combining optical element, characterized in that it includes a camera, a telecentric imaging lens, an image combining optical element and a semiconductor grain arranged in sequence in a vertical light path direction, a trapezoidal image transfer prism is provided on the upper and lower sides between the image combining optical element and the semiconductor grain, and the top surface and the bottom surface of the semiconductor grain are imaged on different regional positions on the camera sensor surface through the trapezoidal image transfer prism and the image combining optical element in a dual light path.

[0010] Furthermore, the sky surface of the above-mentioned image combining optical element close to the camera is a plane, which is the image combining output surface of the dual light path. The sky surface of the image combining optical element is perpendicular to the optical axis of the camera. The left plane and the right plane of the image combining optical element are respectively the dual light path imaging input surfaces, and are parallel to the optical axis of the camera. The center of the bottom hole diameter of the image combining optical element far away from the camera and perpendicular to the optical axis is a total reflection surface at 90 degrees to each other, and the total reflection surfaces at 90 degrees to each other constitute the total reflection surface in the V-shaped groove.

[0011] Furthermore, the above-mentioned image combining optical element is in the shape of a cuboid, and its size is 20x10x20mm, wherein the height from the vertex of the total reflection surface in the V-shaped groove of the bottom surface to the bottom surface is 5mm.

[0012] Furthermore, the position of the image combining optical element along the optical axis of the camera is adjusted, and the interval between the double-sided images of the grains on the output surface is △≈d+a=3.3mm, wherein the interval between the edges of the double-sided images of the grains close to each other is d=2mm, the size of the grain is a=1.3mm, and the distance from the center of the measured surface of the grain to the vertex of the right-angle reflection surface on the input surface is △ / 2.

[0013] Furthermore, the above-mentioned image combining optical element is formed by glass or optical plastic molding, or is formed by two right-angle reflection prisms processed, glued and spliced ​​together, or the two spliced ​​surfaces are bonded together by optical gluing method.

[0014] Furthermore, the side of the trapezoidal image transfer prism away from the camera optical axis is the small end, that is, the top surface of the trapezoidal image transfer prism, and the side close to the camera optical axis is the large end, that is, the bottom surface of the trapezoidal image transfer prism. The top surface and the bottom surface of the trapezoidal image transfer prism are optical surfaces, and the two inclined surfaces are total reflection surfaces. The aperture edge of the bottom surface of the trapezoidal image transfer prism serves the image transfer function, and the middle part between the top surface and the bottom surface is the transmission light path of the illumination light source.

[0015] Furthermore, the above device is provided with an illumination light source, and the illumination light source is located on a side of the trapezoidal image transfer prism away from the camera optical axis direction.

[0016] The present invention is a detection method for simultaneous equal-optical-path imaging and equal-illuminance illumination of double-sided grains based on a combined-image optical element, characterized in that: the detection device for simultaneous equal-optical-path imaging and equal-illuminance illumination of double-sided grains based on a combined-image optical element comprises a camera, a telecentric imaging lens, a combined-image optical element and a semiconductor grain arranged in sequence in a vertical light path direction, a trapezoidal image transfer prism is arranged on both sides between the combined-image optical element and the semiconductor grain, and two side surfaces of the semiconductor grain are imaged on different regional positions on the camera sensor surface by means of a double light path through the trapezoidal image transfer prism and the combined-image optical element; when working, The left side of the illuminated semiconductor crystal grain is successively imaged 180 degrees by the two inclined surfaces of the trapezoidal image-transfer prism, and then imaged 90 degrees by the image-combining optical element, and then imaged on the left half area of ​​the camera sensor surface by the telecentric imaging lens; as for the right side of the semiconductor crystal grain, it is imaged on the right half area of ​​the camera sensor surface by the telecentric imaging lens after passing through the two inclined surfaces of another trapezoidal image-transfer prism and the image-combining optical element; the images of the left and right sides of the semiconductor crystal grain are also obtained from the imaging surface of the camera at the same time, and the image of the left side of the semiconductor crystal grain and the image of the right side of the semiconductor crystal grain are separated by a small distance.

[0017] The present invention provides a detection method for simultaneous equal-optical-path imaging and equal-illuminance illumination of double-sided grains based on a combined-image optical element, characterized in that: the detection device for simultaneous equal-optical-path imaging and equal-illuminance illumination of double-sided grains based on a combined-image optical element comprises a camera, a telecentric imaging lens, a combined-image optical element and a semiconductor grain arranged in sequence in a vertical light path direction, a trapezoidal image transfer prism is arranged on the upper and lower sides between the combined-image optical element and the semiconductor grain, and the top surface and the bottom surface of the semiconductor grain are imaged at different regional positions on the camera sensor surface through the trapezoidal image transfer prism and the combined-image optical element in a dual light path, respectively; During operation, the top surface of the illuminated semiconductor crystal grain is successively imaged by 180 degrees through the two inclined surfaces of the trapezoidal image-transfer prism, and then imaged by 90 degrees through the image-combining optical element, and then imaged by the telecentric imaging lens on the left half area of ​​the camera sensor surface; as for the bottom surface of the semiconductor crystal grain, it is imaged by the telecentric imaging lens on the right half area of ​​the camera sensor surface after passing through the two inclined surfaces of another trapezoidal image-transfer prism and the image-combining optical element; the images of the top surface and the bottom surface of the semiconductor crystal grain are also obtained simultaneously on the imaging surface of the camera, and there is a small gap between the image of the top surface of the semiconductor crystal grain and the image of the bottom surface of the semiconductor crystal grain.

[0018] The technical advantages of the present invention are as follows:

[0019] ① The image combining function of the double-sided imaging optical path is realized by replacing two independent right-angle image-turning prisms with a single image combining optical element. This solution has a simple assembly structure, is easier and more convenient to debug the image combining optical path, and has a higher double-sided image combining accuracy.

[0020] ② The image combining optical element still uses total reflection to realize the image transfer function. It is not necessary to coat the reflective surface with a medium high-reflective film or other high-reflective film like a single right-angle double-sided reflecting prism.

[0021] ③ The interval between the two-sided images of the grain is adjustable and controllable, which can be achieved by fine-tuning the image-forming optical element along the optical axis.

[0022] ④ The use of the trapezoidal image transfer prism simplifies the illumination source system. This solution is better than the illumination source system containing a wedge-shaped refracting prism or a right-angle beam splitter prism proposed in the previous patent ( Figure 3 , 4, 5) The structure is simpler, assembly and debugging are easier, energy utilization is higher, and the cost is lower. Description of the drawings:

[0024] Figure 1 , 2 , 3, 4, and 5 are existing devices for optically inspecting the surface of semiconductor grains;

[0025] Figure 6 , 7 It is a device for optically inspecting the two sides of a semiconductor crystal grain according to the present invention;

[0026] Figure 8 It is the size parameter diagram of the image combining optical element;

[0027] Fig. 9 This is the dimension parameter diagram of the trapezoidal image-transfer prism. Specific implementation method:

[0029] The detection device of the present invention for simultaneous equal-optical-path imaging and equal-illuminance illumination of both sides of a grain based on a combined imaging optical element comprises a camera 1, a telecentric imaging lens 2, a combined imaging optical element 3 and a semiconductor grain 4 arranged in sequence in a vertical optical path direction. The semiconductor grain 4 can be placed on a stage 5. Trapezoidal image transfer prisms 6 are provided on both sides between the combined imaging optical element and the semiconductor grain. The two side surfaces 401 of the semiconductor grain are respectively imaged by two trapezoidal image transfer prisms 6a, 6b and the combined imaging optical element 3 in a dual-optical-path imaging manner and are imaged at different regional positions on the sensor surface of the camera 1.

[0030] Alternatively, the detection device of the present invention for simultaneous equal-optical-path imaging and equal-illuminance illumination of both sides of a grain based on a combined imaging optical element includes a camera 1, a telecentric imaging lens 2, a combined imaging optical element 3 and a semiconductor grain 4 arranged in sequence in the direction of the vertical optical path. The semiconductor grain 4 can be placed on a stage 5. Trapezoidal image transfer prisms 6 are provided on the upper and lower sides between the combined imaging optical element 3 and the semiconductor grain 4. The top surface 402 and the bottom surface 403 of the semiconductor grain are imaged at different regional positions on the sensor surface of the camera 1 by two trapezoidal image transfer prisms 6a, 6b and the combined imaging optical element 3 respectively in a dual optical path.

[0031] The structures of the image combining optical element 3 and the trapezoidal image conversion prism 6 are described in detail below.

[0032] The sky surface 301 of the image combining optical element close to the camera is a plane, which is the image combining output surface of the dual light paths. The sky surface of the image combining optical element is perpendicular to the optical axis of the camera. The left plane 302 and the right plane 303 of the image combining optical element are respectively the dual light path imaging input surfaces, and are parallel to the optical axis K of the camera. The bottom hole diameter center of the image combining optical element far away from the camera and perpendicular to the optical axis K is a total reflection surface at 90 degrees to each other, and the total reflection surfaces at 90 degrees to each other constitute the total reflection surface in the V-shaped groove.

[0033] The image combining optical element is in the shape of a rectangular parallelepiped, with a size of 20x10x20mm, wherein the height from the vertex of the total reflection surface in the V-shaped groove on the bottom surface to the bottom surface is 5mm; the image combining optical element is molded from glass or optical plastic, or is formed by processing, gluing and splicing two right-angle reflection prisms, or the two splicing surfaces are bonded together by optical gluing.

[0034] By moving the image combining optical element 3 along the optical axis, the interval between the images of the two sides of the semiconductor grain on the camera sensor can be adjusted. The size of the interval needs to be selected reasonably. If it is too small, it will be inconvenient for image recognition processing, and if it is too large, it will affect the field of view of the lens.

[0035] The optical prism assembly with dual light path image combining function of the present application is placed at a proper position before the imaging lens so as to obtain the expected double-sided image on the sensor of the imaging lens.

[0036] Furthermore, the position of the image combining optical element along the optical axis of the camera is adjusted, and the interval between the double-sided images of the grains on the output surface is △≈d+a=3.3mm, wherein the interval between the edges of the double-sided images of the grains close to each other is d=2mm, the size of the grain is a=1.3mm, and the distance from the center of the measured surface of the grain to the vertex of the right-angle reflection surface on the input surface is △ / 2.

[0037] The side of the trapezoidal image transfer prism 6 away from the camera optical axis is the small end, that is, the top surface 601 of the trapezoidal image transfer prism, and the side close to the camera optical axis is the large end, that is, the bottom surface 602 of the trapezoidal image transfer prism. The top surface and the bottom surface of the trapezoidal image transfer prism are optical surfaces, and the two inclined surfaces 603 are total reflection surfaces. The aperture edge of the bottom surface of the trapezoidal image transfer prism functions as an image transfer function, and the middle part between the top surface and the bottom surface is the transmission light path of the illumination light source.

[0038] The device of the present application is provided with illumination light sources 7a and 7b, and the illumination light sources are located on the side of the trapezoidal image transfer prism away from the camera optical axis direction; the above-mentioned camera is a camera with a sensor CCD or CMOS.

[0039] by Figure 6 , 7 For example, the present invention is a detection method for simultaneous equal optical path imaging and equal illumination illumination of both sides of a grain based on a combined imaging optical element. The detection device includes a camera 1, a telecentric imaging lens 2, a combined imaging optical element 3 and a semiconductor grain 4 which are sequentially arranged in a vertical optical path direction. The semiconductor grain 4 can be placed on a stage 5. Trapezoidal image transfer prisms 6 are provided on both sides between the combined imaging optical element and the semiconductor grain. Two side surfaces 401 of the semiconductor grain are respectively imaged by two trapezoidal image transfer prisms 6a, 6b and the combined imaging optical element 3 in a dual optical path imaging manner and are imaged at different regional positions on the sensor surface of the camera 1. Working When the left side of the illuminated semiconductor crystal grain is illuminated, it is successively imaged by the two inclined surfaces of the trapezoidal image-transfer prism at 180 degrees, and then imaged by the image-combining optical element at 90 degrees, and then imaged by the telecentric imaging lens on the left half area of ​​the camera sensor surface; as for the right side of the semiconductor crystal grain, it is imaged by the telecentric imaging lens on the right half area of ​​the camera sensor surface after passing through the two inclined surfaces of another trapezoidal image-transfer prism and the image-combining optical element; the images of the left and right sides of the semiconductor crystal grain are also obtained from the imaging surface of the camera at the same time, and the image of the left side of the semiconductor crystal grain and the image of the right side of the semiconductor crystal grain are separated by a small distance.

[0040] Similarly, for the simultaneous detection of the top and bottom surfaces of the semiconductor die, a similar detection device as above can also be applied, except that the trapezoidal image transfer prisms need to be respectively arranged on the top and bottom surfaces of the semiconductor die, and the camera 1, the imaging lens 2 and the image combining optical element 3 are arranged on the semiconductor die in the horizontal optical path direction, such as Figure 7As shown, the detection device for simultaneous equal optical path imaging and equal illumination illumination of double-sided grains based on the combined imaging optical element of the present invention comprises a camera 1, a telecentric imaging lens 2, a combined imaging optical element 3 and a semiconductor grain 4 arranged in sequence in the vertical optical path direction, the semiconductor grain 4 can be placed on a stage 5, and trapezoidal image transfer prisms 6 are arranged on the upper and lower sides between the combined imaging optical element 3 and the semiconductor grain 4, and the top surface 402 and the bottom surface 403 of the semiconductor grain are respectively imaged on different regional positions on the sensor surface of the camera 1 through two trapezoidal image transfer prisms 6a, 6b and the combined imaging optical element 3 in a dual optical path. When working, the top surface of the illuminated semiconductor crystal grain is successively imaged by 180 degrees through the two inclined surfaces of the trapezoidal image-transfer prism and then imaged by 90 degrees through the image-combining optical element, and then imaged by the telecentric imaging lens on the left half area of ​​the camera sensor surface; as for the bottom surface of the semiconductor crystal grain, it is imaged by the telecentric imaging lens on the right half area of ​​the camera sensor surface after passing through the two inclined surfaces of another trapezoidal image-transfer prism and the image-combining optical element; the images of the top surface and the bottom surface of the semiconductor crystal grain are also obtained from the imaging surface of the camera at the same time, and there is a small gap between the image of the top surface of the semiconductor crystal grain and the image of the bottom surface of the semiconductor crystal grain.

[0041] The technical advantages of the present invention are as follows:

[0042] ① The image combining function of the double-sided imaging optical path is realized by replacing two independent right-angle image-turning prisms with a single image combining optical element. This solution has a simple assembly structure, is easier and more convenient to debug the image combining optical path, and has a higher double-sided image combining accuracy.

[0043] ② The image combining optical element still uses total reflection to realize the image transfer function. It is not necessary to coat the reflective surface with a medium high-reflective film or other high-reflective film like a single right-angle double-sided reflecting prism.

[0044] ③ The interval between the two-sided images of the grain is adjustable and controllable, which can be achieved by fine-tuning the image-forming optical element along the optical axis.

[0045] ④ The use of the trapezoidal image transfer prism simplifies the illumination source system. This solution is better than the illumination source system containing a wedge-shaped refracting prism or a right-angle beam splitter prism proposed in the previous patent ( Figure 3 , 4, 5) The structure is simpler, assembly and debugging are easier, energy utilization is higher, and the cost is lower.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A detection device based on a combined image optical element for simultaneous equal optical path imaging and equal illumination illumination of both sides of a grain, characterized by: The invention comprises a camera, a telecentric imaging lens, an image combining optical element and a semiconductor crystal grain which are sequentially arranged in a direction perpendicular to the optical path. Trapezoidal image transfer prisms are arranged on both sides between the image combining optical element and the semiconductor crystal grain. Two side surfaces of the semiconductor crystal grain are imaged on different areas on the camera sensor surface by dual optical paths through the trapezoidal image transfer prism and the image combining optical element respectively. The sky surface of the image combining optical element close to the camera is a plane which is the image combining output surface of the dual optical paths. The sky surface of the image combining optical element is perpendicular to the optical axis of the camera. The left plane and the right plane of the image combining optical element are the dual optical path imaging input surfaces respectively and are parallel to the optical axis of the camera. The bottom hole diameter center of the image combining optical element which is far away from the camera and perpendicular to the optical axis is a total reflection surface which is 90 degrees to each other. The total reflection surfaces which are 90 degrees to each other constitute the total reflection surface in the V-shaped groove. The image combining optical element is adjusted along the phase The position in the direction of the optical axis of the machine, the interval between the double-sided images of the grains on the output surface is △≈d+a=3.3mm, wherein the interval between the edges of the double-sided images of the grains close to each other is d=2mm, the size of the grains is a=1.3mm, and the distance from the center of the surface to be measured of the grain to the vertex of the right-angle reflection surface on the input surface is △ / 2; the side of the trapezoidal image transfer prism away from the camera optical axis is the small end, that is, the top surface of the trapezoidal image transfer prism, and the side close to the camera optical axis is the large end, that is, the bottom surface of the trapezoidal image transfer prism, the top surface and the bottom surface of the trapezoidal image transfer prism are optical surfaces, the two inclined surfaces are total reflection surfaces, the aperture edge of the bottom surface of the trapezoidal image transfer prism functions as an image transfer function, and the middle part between the top surface and the bottom surface is the transmission light path of the illumination light source; the device is provided with an illumination light source, and the illumination light source is located on the side of the trapezoidal image transfer prism away from the camera optical axis.

2. A detection device based on a combined image optical element for simultaneous equal optical path imaging and equal illumination illumination of both sides of a grain, characterized in that: The invention comprises a camera, a telecentric imaging lens, an image combining optical element and a semiconductor crystal grain which are sequentially arranged in a direction perpendicular to the optical path. Trapezoidal image transfer prisms are arranged on the upper and lower sides between the image combining optical element and the semiconductor crystal grain. The top surface and the bottom surface of the semiconductor crystal grain are imaged on different areas of the camera sensor surface by dual optical paths through the trapezoidal image transfer prism and the image combining optical element respectively. The top surface of the image combining optical element close to the camera is a plane which is the image combining output surface of the dual optical paths. The top surface of the image combining optical element is perpendicular to the optical axis of the camera. The left plane and the right plane of the image combining optical element are the dual optical path imaging input surfaces respectively and are parallel to the optical axis of the camera. The bottom hole diameter center of the image combining optical element which is far away from the camera and perpendicular to the optical axis is a total reflection surface which is 90 degrees to each other. The total reflection surfaces which are 90 degrees to each other constitute the total reflection surface in the V-shaped groove. Adjust the image combining optical element. Along the camera optical axis direction, the interval between the double-sided images of the grains on the output surface is △≈d+a=3.3mm, wherein the interval between the edges of the double-sided images of the grains close to each other is d=2mm, the size of the grains is a=1.3mm, and the distance from the center of the surface to be measured of the grains to the vertex of the right-angle reflection surface on the input surface is △ / 2; the side of the trapezoidal image transfer prism away from the camera optical axis is the small end, that is, the top surface of the trapezoidal image transfer prism, and the side close to the camera optical axis is the large end, that is, the bottom surface of the trapezoidal image transfer prism, the top surface and the bottom surface of the trapezoidal image transfer prism are optical surfaces, the two inclined surfaces are total reflection surfaces, the aperture edge of the bottom surface of the trapezoidal image transfer prism functions as an image transfer function, and the middle part between the top surface and the bottom surface is the transmission light path of the illumination light source; the device is provided with an illumination light source, and the illumination light source is located on the side of the trapezoidal image transfer prism away from the camera optical axis direction.

3. The detection device based on the image combining optical element for simultaneous equal optical path imaging and equal illumination illumination of grains on both sides according to claim 1 or 2, characterized in that: The image combining optical element is in the shape of a cuboid, with a size of 20x10x20mm, wherein the height from the vertex of the total reflection surface in the V-shaped groove on the bottom surface to the bottom surface is 5mm.

4. The detection device based on the image combining optical element for simultaneous equal optical path imaging and equal illumination illumination of grains on both sides according to claim 1 or 2, characterized in that: The image combining optical element is formed by glass or optical plastic molding, or is formed by two right-angle reflection prisms processed, glued and spliced, or the two spliced ​​surfaces are bonded into one by optical gluing method.

5. A detection method based on simultaneous equal-path imaging and equal-illuminance illumination of double-sided grains by an image combining optical element, characterized in that: A detection device for simultaneous equal-optical-path imaging and equal-illuminance illumination of double-sided grains based on an image combining optical element as described in claim 1 is used; when in operation, the left side of the illuminated semiconductor grain is successively imaged by 180 degrees through the two inclined surfaces of a trapezoidal image-turning prism, and then imaged by 90 degrees through the image combining optical element, and then imaged by a telecentric imaging lens on the left half of the camera sensor surface; as for the right side of the semiconductor grain, it is imaged by a telecentric imaging lens on the right half of the camera sensor surface after passing through two inclined surfaces of another trapezoidal image-turning prism and the image combining optical element; the images of the left and right sides of the semiconductor grain are also obtained simultaneously on the imaging surface of the camera, and the image of the left side of the semiconductor grain is separated from the image of the right side of the semiconductor grain by a small distance.

6. A detection method based on simultaneous equal optical path imaging and equal illumination illumination of both sides of a grain based on a combined image optical element, characterized in that: A detection device for simultaneous equal-optical-path imaging and equal-illuminance illumination of both sides of a grain based on an image combining optical element as described in claim 2; when in operation, the top surface of the illuminated semiconductor grain is successively imaged by 180 degrees through the two inclined surfaces of the trapezoidal image-turning prism, and then imaged by 90 degrees through the image combining optical element, and then imaged by a telecentric imaging lens on the left half of the camera sensor surface; as for the bottom surface of the semiconductor grain, it is imaged by a telecentric imaging lens on the right half of the camera sensor surface after passing through two inclined surfaces of another trapezoidal image-turning prism and the image combining optical element; the images of the top and bottom surfaces of the semiconductor grain are also obtained simultaneously on the imaging surface of the camera, and there is a small gap between the image of the top surface of the semiconductor grain and the image of the bottom surface of the semiconductor grain.

Images